How to find the number of days between two dates in java or groovy?

Question

I have a method which uses following logic to calculate difference between days.

long diff = milliseconds2 - milliseconds1;
long diffDays = diff / (24 * 60 *         


        

Answer 1

This assumes times are in UTC or GMT.

long day1 = milliseconds1/ (24 * 60 * 60 * 1000);
long day2 = milliseconds2/ (24 * 60 * 60 * 1000);
// the difference plus one to be inclusive of all days
long intervalDays = day2 - day1 + 1;